In the absence of provisions to the contrary, a volume measuring type gas meter will register the actual volume of gas being passed therethrough. However, where density changes of the gas are incurred in transmission from prevailing conditions of pressure and/or temperature, failure to correct for these changing parameters can result in substantial error and inaccuracy in the meter readout. In the instance of natural gas being supplied as fuel, it is, of course, recognized that the commodity of interest resides not in its volume but rather in its calorific content by unit of weight. Failure to correct therefore for prevailing conditions of temperature and/or pressure can result in significant economic advantages or disadvantages to both the vendor and/or purchaser of the gas line product. It is therefore usually desirable to correct the actual measured volume to the corresponding volume as if measured at a standard base condition of pressure and temperature.
A variety of devices for effecting such corrections have been developed over the years, many of which have only amounted to close approximations from failure to operate in close accordance with the gas laws. Mechanical-type equipment for correcting temperature and/or pressure parameters is disclosed, for example, in U.S. Pat. Nos. 2,059,547; 2,093,151; 2,122,529; 3,169,399 and 4,111,042. Electronic approaches to effecting such corrections are disclosed, for example, in U.S. Pat. Nos. 3,537,312; 3,588,481; 3,605,497; 3,831,011 and 3,862,405. Characterizing the mechanical correction units is the complexity of cams, gears, linkages, etc. and associated sluggishness of the mechanisms by which they operate. On the other hand, the electronic devices while representing significant simplification over the mechanical devices have nonetheless been characterized by an excessive number of procedural steps with their corresponding number of operating components for achieving the sought after corrections. While these limitations of the prior art have been recognized, it has not heretofore been known how to effect temperature and/or pressure correction with relatively greater simplification while continuing to operate in conformance with the gas laws.